The present invention relates generally to the field of tackless strips of the type useful to hold wall to wall carpets in place, and more particularly, is directed to an automatic machine for the manufacture of tackless strips.
Tackless strips or pin boards are usually about 1/4 inch in thickness, about 1 1/10 inches wide and 48 inches long. The tackless strips contain a plurality of similarly inclined pins which project upwardly to engage the peripheral undersurface of the carpet and a plurality of downwardly projecting nails for attaching the strips to the floor. Many manual operations were required to fabricate such tackless strips and prior workers have long sought to automate the manufacturing process. One successful apparatus is disclosed in U.S. Pat. No. 3,514,028, which patent is owned by the assignee of the present application.
The prior patented apparatus incorporated a first nailing station wherein a plurality of small sharp pins were angularly applied to one surface of the strip or board. An endless belt was employed to transport each strip with the pins applied to a second nailing station wherein a plurality of the downwardly projecting nails were driven through the board in transversely spaced intervals in a direction opposite to the direction of the pins. Intermediate the first and second nailing stations was provided a strip turnover means which functioned to turn over the strip through one hundred and eighty degrees between the first nailing station and the second nailing station whereby the pins could be driven into one flat surface of the board and the nails could be inserted through the second flat surface of the board.
The prior art turnover means was and is a constant source of operational difficulties whereby slight defects in the wood, such as warping or slight misalignment of the strips during transportation was often sufficient to prevent proper turnover function, which could result in a defective pin strip, or worse, in a jammed machine. The present invention seeks to overcome the turnover problems inherent in the existing automatic pin board manufacturing machines by providing a positive, reliable turnover mechanism which is capable of continuous trouble free operation and which is compatible for use with existing automatic tackless strip manufacturing machines.